Background: The relationship between osteoarthritis (OA) and risk of dementia and cognitive impairment (CIM) has long been debated; however, uncertainties still persist.
Objective: The aim of our present meta-analysis and systematic review was to roundly illuminate the association between OA and the risk of dementia and CIM.
Methods: We identified relevant studies by searching PubMed, Embase, and Web of Science up to October 2021. The relative risk (RR) or odds ratio (OR) with 95% confidence interval (CI) were aggregated using random-effects methods. Credibility of each meta-analysis was assessed. Meta-regression and subgroup analyses were conducted. Publication bias was explored using funnel plot.
Results: Of 21,925 identified literatures, 8 were eligible for inclusion in the systematic review and 19 observational studies involving 724,351 individuals were included in the meta-analysis. The risk of developing dementia and CIM among OA patients was demonstrated in 11 prospective studies (RR = 1.42, 95% CI = 1.07-1.86, I2 = 98.9%, p < 0.001), 2 retrospective cohort studies (RR = 1.35, 95% CI = 1.19-1.52, I2 = 61.0%, p = 0.109), 3 retrospective case-control studies (OR = 1.21, 95% CI = 0.96-1.53, I2 = 95.2%, p < 0.001), and 4 cross-sectional studies (OR = 1.51, 95% CI = 1.09-2.09, I2 = 75.8%, p = 0.006). Meta-regression analyses did not find any valid moderators. Heterogeneity in subgroup analyses for population age, OA location, year of publication, outcome type, adjusted for BMI, depression, and comorbidity decreased to zero. No significant evidence of publication bias was found.
Conclusion: OA associated with an increased risk of dementia and CIM. Effective interventions in OA patients may decrease new incidence of dementia or CIM.
Keywords: Dementia; meta-analysis; osteoarthritis; systematic review.